Title
The Alternating BWT: An algorithmic perspective
Abstract
The Burrows-Wheeler Transform (BWT) is a word transformation introduced in 1994 for Data Compression. It has become a fundamental tool for designing self-indexing data structures, with important applications in several areas in science and engineering. The Alternating Burrows-Wheeler Transform (ABWT) is another transformation recently introduced in Gessel et al. (2012) [21] and studied in the field of Combinatorics on Words. It is analogous to the BWT, except that it uses an alternating lexicographical order instead of the usual one. Building on results in Giancarlo et al. (2018) [23], where we have shown that BWT and ABWT are part of a larger class of reversible transformations, here we provide a combinatorial and algorithmic study of the novel transform ABWT. We establish a deep analogy between BWT and ABWT by proving they are the only ones in the above mentioned class to be rank-invertible, a novel notion guaranteeing efficient invertibility. In addition, we show that the backward-search procedure can be efficiently generalized to the ABWT; this result implies that also the ABWT can be used as a basis for efficient compressed full text indices. Finally, we prove that the ABWT can be efficiently computed by using a combination of the Difference Cover suffix sorting algorithm (Kärkkäinen et al., 2006 [28]) with a linear time algorithm for finding the minimal cyclic rotation of a word with respect to the alternating lexicographical order.
Year
DOI
Venue
2020
10.1016/j.tcs.2019.11.002
Theoretical Computer Science
Keywords
Field
DocType
Alternating Burrows-Wheeler Transform,Rank-invertibility,Difference cover algorithm,Galois word
Data structure,Discrete mathematics,Suffix,Lexicographical order,Analogy,Data compression,Time complexity,Mathematics,Sorting algorithm,Combinatorics on words
Journal
Volume
ISSN
Citations 
812
0304-3975
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Raffaele Giancarlo11112107.23
Giovanni Manzini21584111.42
Antonio Restivo3697107.05
Giovanna Rosone419321.77
Marinella Sciortino522522.34